Page 67 - Demo

Step I. Triggering
This step begins when the sky in the target area is clear or only a few cumulus clouds have formed in the morning and the average relative humidity is at least 60 percent. Powder of Sodium Chloride (NaCl), is dispersed from aircraft in the upwind side of the target area at the altitude of 7,000-8,000 ft. In order to activate cloud formation, each particle of Sodium Chloride acts as cloud condensation nuclei to absorb moisture and then change vapor into liquid or cloud droplets. The clouds can become bigger with the top reaching the altitude of 10,000 ft.
Step II. Fattening
This step is to make the triggered clouds in the previous step and the natural clouds grow bigger. It starts when the cloud tops of the cumulus clouds formed in Step I reach the altitude of 10,000 ft. and an aircraft disperses powder of calcium chloride (CaCl2) into the clouds at the altitude of 8,000 ft. The heat from the chemical reaction of CaCl2 and moisture will expedite or enhance the updraft of air mass in the cloud. Therefore, the cloud growth increases continuously and the cloud top is higher than in the previous step. Its top can reach the altitude of 15,000 ft where it becomes ‘warm cloud’ (the temperature in the cloud top is higher than 00C). If the updraft is enough, the cloud top can develop until it reaches the altitude of 20,000 ft. where it becomes cold cloud (the temperature in the cloud top is below 00C).
Step III. Attacking
This is the case for warm cloud seeding which starts when the cumulus clouds formed in Step II move along with the wind approaching the target area and the cloud tops reach the altitude of 10,000 feet or higher. One aircraft disperses NaCl
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